Pen



FIG. 1 is a front perspective view of a pen showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side elevational view thereof; the left side elevational view being a mirror image of the right side;

FIG. 4 is a rear view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is an enlarged view thereof taken in the direction of 7—7 in FIG. 2; and,

FIG. 8 is an enlarged cross-sectional view thereof taken in the direction of 8—8 in FIG. 7.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a pen, as shown and described. 